The Clostridium botulinum neurotoxins (BoNTs) are the most toxic proteins known to humans and are classified as Category A Select Agents. They are considered as potential serious threat agents in bioterrorism. The Clostridium botulinum and Neurotoxin Core Facility at the University of Wisconsin is directed by Eric A. Johnson, whose laboratory has 24 years of experience with C. botulinum and BoNT, and is the senior reference source for BoNTs, C. botulinum strains, assay systems, animal models, and other relevant materials. The EAJ laboratory has considerable resources and expertise in various aspects C. botulinum and BoNTs. The primary functions of the Core are preparing BoNTs and associated materials, and assisting investigators within the GLRCE in their research projects. The specific aims are: Acquisition, characterization, and maintenance of strains (currently approx. 650) of Clostridium botulinum and nontoxigenic derivative strains. Production, purification and characterization of all seven serotypes and subtypes of botulinum neurotoxins (BoNTs) and their natural protein complexes. Production, purification, and characterization of recombinant forms of BoNTs, their domains and toxin complexes. Performance of animal studies, including mouse LDSOs, mouse challenges, immunization studies, and BoNT neutralization analyses. Implementation of non-animal assays, particularly neuronal cell assays, for detection and study of BoNTs and inhibitors. Maintain Select Agent Laboratory environment for research with C. botulinum and BoNTs. The Botulism Core will continue collaborations and facilitate the research efforts of other laboratories within the GLRCE.